Effective removal of heat generated from machines in an industrial plant is critical to its function; heat accumulation can be detrimental to manufacturing equipment and can lower operating efficiency. Hence energy efficiency and economics of the overall plant directly depend on the rate of heat removal. Fin-and-fan heat exchangers are commonly used in industrial heating, ventilation and heat exchange systems. Waste heat transfers to the fins, and is dissipated by fans generally through forced air convection. Concomitantly these systems need periodic maintenance to facilitate effective heat removal. Similarly, heat exchange systems including compressor radiator and aerial coolers also require constant maintenance.
Heat exchangers are typically deployed in an open field setting and are constantly exposed to dust, debris, industrial exhaust, chemical residues, high temperatures and potentially corrosive environments. Accumulation of dirt, debris or chemical/organic residues on the fins over time drastically lowers the rate of heat removal. This decreases cooling efficiency of the heat exchangers and can lead to reduced production rates and increase energy costs. These factors highlight the need for periodic cleaning of heat exchangers in order to maintain and enhance their operational efficiency.
Traditional methods for cleaning heat exchange systems include low/high pressure water rinsing, soda blasting and ice blasting. Both low and high pressure water rinsing are not effective against most inorganic residues and can potentially damage the fins. On the other hand, soda and ice blasting methods require multiple cleaning steps that are not effective and are very expensive. The other approach to cleaning the fins is the use of strong caustic liquid chemicals to clean the fin surface. These chemicals can be effective against most dirt and chemical/organic residues. However, the major limitation in using aqueous chemicals and solvents is reduced contact time with the heat exchanger surface.
The current state of the art technique for effective cleaning of heat exchangers is to use foaming agents in tandem with cleaning chemicals. This foaming soap is sprayed directly on the fins. Foaming dramatically increases chemical contact time thereby improving cleaning efficiency. Though effective, foam cleaning can be limited because these liquid cleaning/foaming agents are required to be stored in a secondary containment. Also, transportation regulations and plant operational safety standards limit the amount of liquid chemicals that can be transported and stored onsite. This increases both the time consumed in cleaning the heat exchangers and overall costs. In addition to liquid chemical handling limitations, complex flow circuits involving heavy-duty water pumps and air compressors are assembled to uniformly mix the liquid chemicals with water and generate preferred foam consistency. The construction, operation and maintenance of these flow circuits add significant capital costs to the cleaning operation.
Indeed, there is a demonstrated demand for a portable device that is capable of generating foam in-situ from chemicals on-site and on-demand.